Timers and the like



Feb. 4, 1964 D. J. ROSS] TIMERS AND THE LIKE Filed Oct. 9, 1959 INVENTOR DOMINIC J. R053! BY 820 3412/. 1 ml United States Patent O 3,120,298 TIMERS AND THE LHKE Dominic J. Rossi, Philadelphia, Pa, assignor to Automatic Timing and Controls, Inc, King of Prussia, Pa., a corporation of Pennsylvania Filed Oct. 9, 1959, Ser. No. 345,528 21 Claims. (Cl. 192--.02)

This invention relates to timers of the automatic type and more particularly to a reverse motion stopping mechanism for timers, counters and the like, which have a spring reset timing or counting element or the like. Such a reverse motion stopping mechanism prevents back movement of the elements of the device when its source of motive power is disengaged or inactivated.

The operation and construction of the invention may best be understood from the following description taken with the accompanying drawing in which:

FIGURE 1 is a perspective schematic view of a timer constructed according to the teachings of United States Patent No. 2,885,001 with the features of the present invention incorporated therein;

FIGURE 2 is a schematic front elevational view of the timer shown in FIGURE 1, partially cut away to show the reverse motion stopping mechanism of the present invention in operation;

FIGURE 3 is a rear vertical sectional veiw showing the rear of some of the parts shown in FIGURE 2 and taken along the line 33 of FIGURE 1;

FIGURE 4 is a fragmentary vertical section taken along the line 4-4 of FIGURE 2; and

FIGURE 5 is a rear schematic sectional view (similar to FIGURE 3), of a modified form of reverse motion stopping mechanism also utilizing the features of the invention.

The present invention, an improvement in electromechmical timers, such as the timer disclosed in the previously mentioned United States Patent No. 2,885,001 issued to E. R. Brown on May 5, 1959, can best be understood by reference to FIGURE 1 which schematically shows such a timer having the improvement of the present invention incorporated therein.

The drive motor it} may be a synchronous or other constant speed motor if the apparatus is to be used as a timer or it may be an incremental rotating device where such apparatus is to be a counter or the like. Drive motor rotates a drive shaft 12 through reduction gears 14 and 16. On the opposite end of drive shaft 12 there is a driver gear 118 meshing with a large driven gear 28, rigidly mounted on a sleeve 22 (FIGURE 4). A large disk 24 is fixed to the opposite end of sleeve 22 to be driven by gear 20. There is a resilient O-ring 26 secured to the disk 24; this O-ring 26 may be made of rubber, neoprene or other resilient polymer material. Thus, drive motor 10 rotates disk 24 in the direction indicated by the arrow by way of reduction gears 14 and I6, drive shaft 12, gears 18 and 2t and sleeve 22.

Still referring to FIGURE 1, a settable finger 28 is rotatably mounted (not shown) in front of the large disk 24 and under a suitable face (not shown) having any desired indicia thereon; finger 28 has an inwardly depending detent 36 near its outer end. The finger 28 and its detent 3t? do not constitute part of the present invention and are depicted and explained to the extent shown only to show an illustrative environment in which the present invention may be employed. Reference is made to the previously mentioned Brown patent for details of mounting and operation of this finger. A driven finger 32 is fixed to a shaft 34 which is rotatably mounted within the sleeve 22 and arranged to be axially moved as explained below and also in detail in the aforesaid Brown 3,12%,298 Patented Feb. 4, 1964 patent. Finger 3 2 has an inwardly depending detent 36 which is radially coincident with O-ring 26 on disk 24. In FIGURE 1, detent 36 is engaged with the O-ring 26 so that finger 32 rotates With the disk 24 to rotate shaft 34. As shaft 34 rotates, it winds up a toroidal spring at) having one end secured thereto and if detent 36 is disengaged from the Oring 26, driven finger 32 rotates back against detent 30* on finger 28.

A cut-off switch 42 is suitably mounted in the path of finger 32; it is here shown in a circuit including lines L1 and M1 to control the operation of motor 10. When finger 32 rotates with disk 24 in the direction of the arrow, it finally engages a switch arm 44 of switch 42 to open the motor circuit thereby stopping disk 24. Load lines, generally indicated at 46, may also be controlled by switching element 44.

Still referring to FIGURE 1, a clutch mechanism, generally indicated at 48, is constructed to move shaft 34 axially to engage or disengage the O-ring 26 and finger 3-2. As previously noted, finger 32 is fixed on shaft 34 and spring element 52 is associated therewith to bias the shaft forwardly as viewed in FIGURE 1 to disengage the finger from the 0-ring. Clutehing mechanism 48 comprises a solenoid 54, having an armature 56 which is pivoted about fixture 58 and biased away from the solenoid by an adjustable spring 69. Armature 56 also includes a switch generally indicated at '76 including contacts 72 and 74 which may be used in a variety of controlling circuits as desired. A shoulder 62 on the end of shaft 34 engages a clevis 66, secured to a rocker shaft 66. Shaft 66 is in turn fixed to a rocker arm 63 which is connected to armature 56 by a link 70. Accordingly, when solenoid 54 is energized, arm 68 moves in a clockwise direction as viewed in FIGURE 1 to similarly move clevis 64 against shoulder 62. This moves shaft 34 rearwardly to engage arm 32 and O-ring 26. Deenergization of the solenoid 'has the reverse effect as spring 60 snaps armature 56 in the opposite direction.

In operation, the driven finger 32 rests on detent 30 of the settable finger 28, which may be set at any arcuate position with respect to switch 42. When motor 10 is energized it rotates shaft l2 to rotate gear 20. Because gear 29 is connected to disk 24-, O-ring 26 will commence rotation. To initiate a timing or counting cycle, solenoid 54 is energized to pull the shaft 34 rearwardly causing the detent 36 on driven finger 32 to engage the O-ring 26; and finger 32 thus commences to move toward switch 42 against the biasing torque of toroidal spring 40. When finger 3-2 engages switching element 44, the motor circuit is broken so that the parts come to rest. When solenoid 54 is de-energized the parts will assume their initial position, shaft 34 and driven finger 32 being rotated by spring 40 in the opposite direction until the finger engages detent 3i on the settable finger 28. Alternatively, the device may be made self-resetting by connecting solenoid 54 and motor 10 in series to work as a unit.

This type of timer has an important shortcoming, to wit, when connected as a non-self-resetting device (motor 10, but not solenoid 54, disconnected by switch 42), it may hunt, i.e., refuse to come to rest. More specifically, at the moment of switch engagement spring 40 may quickly assert itself to move shaft 34 in a counterclockwise direction closing switch 42 to reconnect motor 10. Disk 24 will then again rotate in the clockwise direction until switch engagement. Thus a false recycling may continue until the timer is disconnected. This false recycling or hunting may also occur when the apparatus is connected as a self-resetting device (motor 10 and solenoid 54 both disconnected by switch 42), due to the fact that it takes a finite time longer for the clutch mech anism 48 to operate to release driven finger 32 from the O-ring 25 than for the motor Iii to be de-energized. This false recycling or hunting is most likely to occur when the drive motor is a standard synchronous motor of the type having an internal self-disengaging clutch which disengages when the drive motor Til is disconnected from its power source, particularly where short periods of time are being measured by the apparatus; the gears 14- and 16 then having little friction to hold the shaft 12 against reverse motion. Thus recycling is most likely to occur when the apparatus is used as a seconds interval timer, e.g., for intervals on the order of to 30 seconds.

Accordingly, it is a principal object of the present invention to provide an improved electromechanical timing or counting device.

Another object of the invention is to provide an improved electromechanical timing or counting device of the above character that is free from false recycling.

Still another object of the invention is to provide a device of the above character that is free from false recycling particularly when connected as a non-reset device.

Yet another object of the invention is to provide a device of the above character free from false recycling when used as a short time interval timer.

Still another object of the invention is to provide a device of the above character free from false recycling when used as a counter.

A further object of the invention is to provide a device of the above character at a reduced cost.

A still further object of the invention is to provide a reverse motion stopping mechanism for use in devices of the above character.

Yet a further object of the invention is to provide a reverse motion stopping mechanism of the above character adaptable to many different forms of rotational transmission systems used in timing or counting devices.

Another object of the invention is to provide a reverse motion stopping mechanism of the above character for use in the gear train of a timing or counting device, which is capable of stopping a gear within one tooth width or less of rotation.

A further object of the invention is to provide a reverse motion stopping mechanism of the above character which facilitates the accomplishment of the above objects when incorporated into the improved timing or counting devices mentioned above.

Other objects of the invention will in part be obvious and will in part appear hereinafter.

The invention accordingly comprises the features of construction, combinations of elements, and arrangements of parts which will be exemplified in the constructions hereinafter set forth, and the scope of the invention will be indicated in the claims.

Referring to FIGURES l, 2, 3 and 4, the reverse motion stopping mechanism of the present invention comprises an idler gear 78 which is rotatably mounted on a shaft til fixed to an arm 82 rotatably mounted on shaft 12. A collar 88 is fixed to shaft 12 to rotate therewith and to hold arm 82 in position thereon. In this manner gear '78 is supported to mesh with driver gear 18. As can best be seen in FIGURE 3, an extension 82a of arm 82 engages a stop member 86 when gear 18 and driven gear 20 rotate in the directions shown by the arrows in FIGURE 1. As shown in FIGURE 1, shaft 12, as well as collar 88, rotate in counterclockwise direction and the friction between the collar and arm 82 moves it away from driven gear 20. Accordingly, during operation with parts rotating as indicated in FIGURE 1 and finger 32 moving toward switch 42, idler gear 78 is held disengaged from gear 20. When finger 32 hits switch arm 44 to stop motor It), spring 40 commences to rotate shaft 34 and disk 24 in an opposite or counterclockwise direction as seen in FIGURE 1. As can be best seen in FIGURE 2, this counterclockwise rotation drives gear 13 and shaft 12 in a clockwise direction. The friction between arm 82 and collar 88 (FIG- URES 3 and 4) causes the arm to move toward gear 20 as shown by the arrow in FIGURE 2 to bring idler gear '78 into mesh therewith to halt its counterclockwise rotation. These parts are proportioned and positioned to achieve this locking action almost instantaneously thereby preventing disengagement of finger 32. and switch arm 44 and allowing the clutch mechanism to move finger 32 away from O-ring 26. It has been found that the idler gear '73 will engage the driven gear 2%) within one tooth width of rotation and that false recycling and hunting are completely prevented in the device by this reverse motion stopping mechanism.

Referring now to FIGURE 5, a modification of the present invention also is mounted in association with gears 18 and 2t) and the direction of rotations is indicated by the arrows therein. Here, an idler gear 9% is rotatably mounted on a shaft 92 fixed to an idler arm 94 which is, in turn, rotatably mounted on sleeve 22. There is a certain amount of friction between the idler arm 94 and sleeve 22, producing a torque on idler arm 94 rotating it in the same direction as gear 20, as indicated by the small arrow on arm 94. A stop 96 prevents arm 94 from rotating very far with gear 29. Thus, when gears 18 and 2%) reverse rotation at the end of a cycle as previously described, idler arm 94 immediately moves gear into mesh with gear 18 to stop such reverse motion.

As will be obvious to those skilled in the art, the reverse motion stopping mechanisms described above may be used in any timer, counter or the like, having a rotary motion transmission, with an arcuately biased, driven control element connected to the transmission through a clutching device. In particular, the usefulness of the present invention is not limited to timers having the particular clutching arrangement shown herein including O-ring 26 and driven finger 32.

It will thus be seen that the objects set forth above, among those made apparent from the preceding description, are eificiently attained and, since certain changes may be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.

It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention which, as a matter of language, might be said to fall therebetween.

Having described my invention, what I claim as new and desire to secure by Letters Patent is:

1. A reverse-motion stopping mechanism for use in timing and counting dev-ices comprising, in combination, a motor, a rotatable driver gear mounted for connection with said motor, a rotatable driven gear mounted to mesh with said driver gear, a rotatable control element which indicates rotary movement of said driven gear, means adapted to form a driving connection between said control element and said driven gear, an arm mounted adjacent to a selected one of said two gears for rotation about the axis thereof, a rotatable idler gear mounted on said arm meshing with said selected gear, and coupling means associated with said selected gear and said arm for urging said arm to rotate so that the other of said two gears also meshes with said idler upon any reversal of motion of said driven gear.

2. The combination of claim 1 and a stop adapted to limit the rotation of said arm when it rotates away from said other gear.

3. A reverse-motion stopping mechanism for use in timing and counting devices comprising, in combination, a motor, a rotatable drive shaft mounted for connection with said motor, a driver gear fixed to said drive shaft, a rotatable driven gear in mesh with said driver gear, a rotatable control element which indicates rotary movement of said driven gear, means adapted to form a driving connection between said control element and said driven gear, an arm rotatably mounted on said shaft adjacent to said driver gear, a rotatable idler gear mounted on said arm in mesh with said driver gear, and coupling means associated with said arm and said driver gear to urge said arm in a rotary direction whereby said idler gear also meshes with said driven gear upon reversal of motion of said driven gear.

4. The combination of claim 3 further defined in that said coupling means is also adapted to urge said arm in a rotary direction whereby said idler gear is out of mesh with said driven gear upon forward motion of said driven gear.

5. The combination of claim 4 and means adapted to limit the separation of said idler gear and said driven gear upon forward rotation of said driven gear.

6. In a timer, counter, or the like, the combination comprising, a rotary motion transmission including first and second meshed gears, a rotatable control element which indicates rotary movement of said gears, an angularly settable initial stop for said control element, a cut-off device for stopping said rotary motion which is adapted to be actuated by said control element, clutch means for connecting said control element in driven relation with one of said transmission gears for driving said control element from said initial stop to actuate said cut-off device, means biasing said control element toward said initial stop when said clutch is disengaged, an arm mounted adjacent to and for rotation about a common axis with said first gear, an idler gear mounted on said arm in driven engagement with said first gear, and means adapted to urge said arm to move generally in the direction of rotation of said first gear so that said idler gear is correspondingly moved into or out of engagement with said second gear depending upon the direction of rotation of said first gear.

7. The combination of claim 6 and a stop for restricting the angle through which said arm may rotate.

8. The combination of claim 7 further defined in that said means adapted to cause said arm to rotate in the direction of rotation of said first gear comprises a frictional coupling between said arm and the said gears and shafts associated therewith.

9. A timer, counter, or the :like, comprising, in combination, a source of rotary motion, a drive shaft driven by said source, a first gear mounted on said shaft for rotation thereby, a second gear in mesh with said first gear, an arm mounted on and rotatable about said shaft and adjacent to said first gear, an idler gear mounted 011 said arm engaged with said first gear and adapted to be rotated by said first gear when said arm is restrained, a stop adapted to limit the rotation of said arm, a rotatable d-riven element, a settable initial stop for said driven element, cut-oft" means in the path of said driven element adapted to de-energize said source of rotary motion, means biasing said driven element against said initial stop, and clutch means for engaging said driven element with said second gear to drive said driven element against said bias until said driven element engages said cut-off means.

10. In a timer, counter, or the like, having a gear train for driving an element against a force-producing biasing means, means for preventing said biasing means from forcing said gear train backwards, comprising, in combination, a rotatable arm mounted on the shaft of one of the gears of said gear train, an idler gear mounted on said arm engaged with said one gear and rotatable thereby when said arm is restrained, means adapted to cause said arm to rotate in the direction of rotation of said one gear, and a stop adapted to engage said arm when it rotates in one direction and prevent further rotation thereof.

11. In a timer, counter, or the like, having a multiple gear transmission connectable to a source of rotary motion, a rotatable driven element connectable through a clutch to said transmission to be driven thereby between an arcuately settable initial stop and a cut-off device and arcuately biased toward said initial stop, said cut-off device adapted to disconnect said source of rotary motion, an improvement for preventing hunting of said driven element when at said cut-off comprising, in combination, an arm rotatably mounted on the shaft of a first gear of said transmission, a rotatable idler gear mounted on said arm in mesh with said first gear, and means adapted to produce a torque on said arm to rotate it and said idler gear into and out of mesh with a second gear of said transmission meshed with said first gear depending upon the direction of rotation of said first gear.

12. The combination of claim 11 and rotational limiting means adapted to restrict the movement of said idler ear away from said second gear.

13. In a timer, counter, or the like, having an electrically-energized motor, a drive shaft driven by said motor, a driver gear fixed to said shaft, a driven gear in mesh with said driver gear, a driven finger engageable with a deformable O-ring, said O-ring being driven by said driven gear, a settable initial stop for said driven finger and said finger being arcuately biased against said stop, a switch ultimately operable by said driven finger when it is engaged with said O-ring, said switch connected in circuit with said motor to de-energize it when operated by said finger, the improvement for preventing hunting of said finger when operating said switch comprising, in combination, an idler arm rotatably mounted on said drive shaft next to said driver gear, a collar fixed to said shaft on the opposite side of said arm, a shaft mounted on said arm, a rotatable idler gear mounted on said shaft and meshed with said driver gear, said parts being so proportional that the friction produced therein results in a net torque on said arm to urge it to rotate with said driver gear.

14, The combination defined in claim 13 further defined in that said arm has an extension integral therewith for engaging a stop to restrict the movement of said idler gear away from said driven gear.

15. In a timer, counter, or the like, having an electrically-energized motor, a drive shaft driven by said motor, a driver gear fixed to said shaft, a driven gear in mesh with said driver gear, a driven finger engageable with a deformable O-ring, said O-ring being driven by said driven gear, a settable initial stop for said driven finger and said finger being arcuately biased againstsaid stop, a switch ultimately operable by said driven finger when it is engaged with said O-ring, said switch connected in circuit with said motor to de-energize it when operated by said finger, the improvement for preventing hunting of said finger when operating said switch comprising, in combination, an idler arm rotatably mounted adjacent to said driven gear, a shaft mounted on said arm, a rotatable idler gear mounted on said shaft and meshed with said driven gear, said parts being so proportional that the friction produced therein results in a net torque on said arm to urge it to rotate with said driven gear.

16. The combination defined in claim 15 and a stop positioned to engage said arm when said motor is energized to restrict the movement of said idler gear away from said driver gear.

17. Apparatus for preventing a gear from rotating in an undesired direction comprising: a first gear, a second gear meshing with said first gear and adapted to drive said first gear in a desired rotary direction, an arm mounted adjacent a selected one of said gears and coupled thereto so as normally to be urged in the same rotary direction as said selected gear, and a third gear mounted on said arm and meshing with said selected gear, said arm being constructed and arranged so that when said first gear commences to rotate in an undesired direction said arm is urged in a rotary direction opposite its normal one thereby moving said third gear also to mesh with the other gear whereupon the simultaneous meshing of all of said gears arrests further movement of said first gear in said undesired direction.

18. The invention according to claim 17 wherein said arm is mounted coaxially with said selected gear and in 5 sliding frictional engagement therewith.

19. The invention according to claim 17 wherein said selected gear is said first gear.

20. The invention according to claim 17 wherein said selected gear is said second gear.

21. The invention according to claim 17 wherein means are provided to limit the position of said arm when it is urged in its normal rotary direction.

References Cited in the file of this patent UNITED STATES PATENTS 2,885,001 Brown May 5, 1959 2,900,049 Kozikowski et a1 Aug. 18, 1959 FOREIGN PATENTS 130,767 Sweden Feb. 6, 1951 

9. A TIMER, COUNTER, OR THE LIKE, COMPRISING, IN COMBINATION, A SOURCE OF ROTARY MOTION, A DRIVE SHAFT DRIVEN BY SAID SOURCE, A FIRST GEAR MOUNTED ON SAID SHAFT FOR ROTATION THEREBY, A SECOND GEAR IN MESH WITH SAID FIRST GEAR, AN ARM MOUNTED ON AND ROTATABLE ABOUT SAID SHAFT AND ADJACENT TO SAID FIRST GEAR, AN IDLER GEAR MOUNTED ON SAID ARM ENGAGED WITH SAID FIRST GEAR AND ADAPTED TO BE ROTATED BY SAID FIRST GEAR WHEN SAID ARM IS RESTRAINED, A STOP ADAPTED TO LIMIT THE ROTATION OF SAID ARM, A ROTATABLE DRIVEN ELEMENT, A SETTABLE INITIAL STOP FOR SAID DRIVEN ELEMENT, CUT-OFF MEANS IN THE PATH OF SAID DRIVEN ELEMENT ADAPTED TO DE-ENERGIZE SAID SOURCE OF ROTARY MOTION, MEANS BIASING SAID DRIVEN ELEMENT AGAINST SAID INITIAL STOP, AND CLUTCH MEANS FOR ENGAGING SAID DRIVEN ELEMENT WITH SAID SECOND GEAR TO DRIVE SAID DRIVEN ELEMENT AGAINST SAID BIAS UNTIL SAID DRIVEN ELEMENT ENGAGES SAID CUT-OFF MEANS. 